Device for cleaning a roller

ABSTRACT

A device for cleaning a roller in a rotary printing press uses a plurality of rotating brushes. Spray nozzles are arranged centrally in each of these rotating brushes. The brushes are supported on a carriage that can be moved along the length of the roller which is to be cleaned.

FIELD OF THE INVENTION

The present invention relates to a device for cleaning a roller of arotary printing press. At least one rotating cleaning element, whoseaxis of rotation is not parallel with the axis of rotation of the rollerto be cleaned, is arranged adjacent that roller. Several cleaningelements, having opposite directions of rotation, can be used.

DESCRIPTION OF THE PRIOR ART

A device for cleaning rollers is known from EP 0 693 378 B1. A brushroller is guided along the roller to be cleaned, and a cleaning fluid issimultaneously introduced into the inlet gap between the two rollers.This prior art device contains a reservoir for cleaning fluid and acatch basin for dirt particles to be removed.

A printing plate cleaning device is known from U.S. Pat. No. 5,148,746.A rotatable brush, in the shape of a truncated cone, and which can bemoistened on the exterior, can be placed obliquely, i.e. at an acuteangle in respect to the radial direction, against the plate cylinder, sothat only a portion of the brush is in contact with the plate surface.In addition, the edge zone of the brush is beveled in such a way that asection of the brush in the shape of an arc of a circle can be broughtinto contact with the plate surface.

EP 0 747 217 A2 discloses a cleaning device for cylinders of printingpresses. Two rotating brushes, which are offset in respect to each otherin the circumferential direction of the cylinder, are provided.

SUMMARY OF THE INVENTION

The object of the present invention is based on providing a device forcleaning a roller of a rotary printing press.

In accordance with the present invention, this object is attained byusing several rotating cleaning elements to clean the roller. Theserotating cleaning elements each have an axis of rotation that is notparallel with the axis of rotation of the roller to be cleaned. Theseveral rotating cleaning elements may have opposite directions ofrotation with respect to each other.

The advantages which can be obtained by the present invention rest, inparticular, in that an evenly cleaned surface of the rollers orcylinders is obtained. Accumulations of ink or dirt are mechanicallyremoved, except for a thin layer, during either running or standstill ofthe press. In case of intense soiling, it is possible to apply acleaning fluid, and the rollers can also be additionally cleaned by therotating brushes.

Furthermore, it is advantageous, in connection with the presentinvention, that it is possible to apply an ink separating agent shortlyprior to the start of printing. The creation of paper waste, which mustbe disposed of as special waste, is prevented by use of the cleaningdevice in accordance with the present invention. Moreover, by removingor preventing the accumulation of dirt on the roller, which roller maybe, for example a paper guide roller, the creation of creases in thepaper web is prevented.

Finally, it is also advantageous that a paper guide roller, which cannotbe driven, can be brought to the required circumferential speed by theauxiliary drive mechanism, for example prior to drawing in a paper web.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present invention are represented in thedrawings and will be described in greater detail in what follows. Shownare in:

FIG. 1, a top plan view on the device for cleaning a roller inaccordance with the present invention in a schematic representation,without the housing and carriage guide,

FIG. 2, a section II—II through the device in accordance with FIG. 1,but showing a paper web and carriage guide, as well as the sectionrotated by 90°, and in

FIG. 3, a top view of a paper guide roller with a device arrangedthereon in the position of rest in a schematic representation with apaper web guide differing from FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A device 01 for cleaning a roller 04, or a cylinder or the like, isarranged in the immediate vicinity of a guide roller 04 that is seatedbetween two lateral frames 02, 03, as seen in FIG. 3. Roller 04 may be,for example, a paper guide roller 04, having an axis of rotation 05. Theroller cleaning device 01 consists of a carriage guide 06, which isarranged axis-parallel with the paper guide roller 04 and is fixed inplace in the lateral frames. Carriage guide 06 receives a carriage 07,which is movable in the x-direction of a right-angled spatial coordinatesystem. The carriage 07 supports an approximately box-shaped housing 08,which has an opening 09 on its side facing the paper guide roller 04,all as seen in FIG. 1.

Cleaning elements, for example two brush holders 11, 12, are placed nextto each other, and are displaceable back and forth in the radialdirection Z of the paper guide roller 04, as seen in FIG. 2. These brushholders 11, 12, which can be fixed in place against the wall of thehousing 08, are arranged inside the housing 08. Each one of the brushholders 11, 12 takes respectively two brushes 13, 14, or 16, 17, whichare arranged above each other. Each brush 13, 14, 16, 17 is respectivelyrotatably seated on a hollow shaft 18 arranged on the brush holder 11,12. Two brushes 13, 14, or 16, 17, located above each other, are drivenby a motor 19, 21 flanged on the brush holder 11, 12, for example anelectric motor, via a gear 22, 23.

Each brush 13, 14, 16, 17 has a rotatable brush head 24 extending in thedirection toward the paper guide roller 04. The brush head 24 isembodied as a front brush with a circle- or ring-shaped bristle trim. Itis also possible to employ small plastic sponges in place of bristles.An axis of rotation 20 of each brush 13, 14, 16, 17 extendsaxis-parallel with the x-axis of the previously mentioned spatialcoordinate system. On its end close to the roller 04, each hollow shaft18 has a spray nozzle 26. A nozzle opening is arranged centered in eachbrush head 24.

The brush heads 24 always turn in opposite directions of rotation. Thisis achieved because the motors 19, or 21, which work together with thepairs of brushes 13, 14, or 16, 17, rotate by turning toward each other.

Only the portions of each brush head 24, which are in the immediatevicinity of an axis 27 extending in the z-direction, as seen in FIG. 2,are in contact with the surface 28 of the paper guide roller 04. Theportions of each brush head 24, which are further removed from thehorizontal axis 27, are not in contact with the surface 28 of the paperguide roller 04.

An axis of rotation 20 of the cleaning elements or brushes 13, 14, 16,17 forms an opening angle of −45° to +45° with a radial line extendingthrough the contact zone between the cleaning elements 13, 14, 16, 17and the roller 04.

The respective hollow shaft 18 of each brush 13, 14, 16, 17 is connectedby a pressure line 29 with a pump unit 31, whose motor 32, which may be,for example an electric motor, is connected by electrical lines 33 withan electrical receptacle 34 fastened on the housing 08. The pump unit31, in turn, is connected via a suction line 36 with a reservoir 37 forfluids, for example a cleaning fluid or a liquid separating agent.

The reservoir 37 has a filling connection 38 for fluids in the vicinityof the housing 08, as well as an associated check valve 39 and anoverflow line 41.

On its lower side, the housing 08 is embodied as a catch basin 42 forfluids and dirt particles. Catch basin 42 is connected, via a suctionline 43, with a disposal connector 45 in the vicinity of the housing, aswell as with an associated check valve 44.

The motors 19, 21 are each connected with the receptacle 34 byelectrical lines 68, 69.

A carriage drive belt 49 is arranged within the carriage guide 06, asseen in FIGS., 2 and 3 via a belt drive pulley 46, which pulley 46 isdriven by a motor 47, for example an electric motor. Carriage drive belt49 is further supported by, for example, three further belt reversingpulleys 48, and is guided between the lateral frames 02, 03. Each of thecarriage drive belt pulleys 46, 48 is rotatably seated on a journal 51fixed in place on the carriage. The carriage drive belt 49 is releasableconnected with the carriage 07 by means of a coupling 52, for example abolt with a clamping device. The carriage drive belt drive pulley motor47 is connected via an electrical line 50 with the central electricalline 88, as shown in FIG. 3.

The carriage 07 has a contact piece 65, for example, a bolt as shown inFIG. 2, which is fixed on the carriage, and which, during the back-and-forth movement of the carriage 07 into a left or a right endposition A or B shown in FIG. 3, is in contact with an end positionsensor 53 or 54 fixed on the carriage guide 06, as seen in FIGS. 2 and3. The end position sensors 53, 54 are each connected, via electricallines 86, 87, with the central electrical line 88 to the press controlconsole. The same applies for the electrical receptacle 34. The motor 47of the carriage drive belt drive pulley mechanism can be switched off bythe end position sensors 53 or 54.

If a paper guide roller 04 is without its own drive mechanism, orwithout external drive, as provided by a paper web, the carriage 07 canbe provided with an auxiliary paper guide roller drive mechanism,generally at 56.

This auxiliary paper guide roller drive mechanism 56 consists of atwo-armed lever 58, for example, which is pivotably arranged, at a firstend, on a shaft 57 seated fixed in place on the carriage, and whichlever 58 supports, on its second end close to the paper guide roller 04,a rotatably seated shaft 59 with a drive pulley 61, for example coatedwith rubber, and a belt pulley 62, arranged fixed against relativerotation in respect to the shaft 59, of a belt drive 63. A drive pulley64 of the belt drive 63 is connected, fixed against relative rotation,with the support shaft 57, which drive pulley 64 is driven by a motor66, for example an electric motor, all as may be seen in FIG. 1.

The second end of the lever 58 can be pivoted about shaft 57 and againstthe force of a spring, not specifically represented, by switching on alift magnet 67, so that the drive pulley 61 is placed against the paperguide roller 04.

The motor 66, as well as the lift magnet 67, are each connected with thereceptacle 34 by common electrical lines 71, so that when the motor 66is switched on, the lever 58 with the drive pulley 61 located on it isalso simultaneously pivoted away. With the appropriate activation of themotor 66, as well as the lift magnet 67, by means of an electricalsignal issued at the start of the draw-in process, this auxiliary drive56 can also be used to accelerate a non-driven paper guide roller 04 tothe required circumferential speed prior to the draw-in of the paperweb. It is a prerequisite for this that the carriage 07 is locatedbetween the end positions A, B.

The acceleration of the paper guide roller 04 by means of the paper webto be drawn in, and therefore the premature soiling of the paper guideroller, is avoided by this.

The carriage 07 furthermore has one or two doctor blade devices 72, 73,as shown in FIGS. 1 and 2. Each one of the doctor blade devices 72, 73is arranged at the left, or right, end of the x-axis of the carriage 07in an area close to the paper guide roller. Each one of the doctor bladedevices 72, 73 consists of one or more doctor blades, for example threeround, or preferably polygonal, for example octagonal, doctor blades 74,75, 76 each made of a thin material, for example of anabrasion-resistant plastic material, for example polyamide,approximately 1 mm thick, or of brass. By use of a holding device 78,fixed in place on the carriage, the doctor blade disks 74 to 76 arearranged overlapping each other and rotatable around a center axis insuch a way, that one of their eight work edges 79 always rests on animaginary straight operating line 81.

The straight operating line 81 extends at an acute angle α of, forexample 3° to 8°, in respect to an imaginary line 84, extending on thesurface 28 of the paper guide roller 04 parallel with the axis ofrotation of roller 04, as seen in FIG. 1, so that the distance of thework edges 79 of the doctor blade disks 74 to 76 from the line 84respectively increases in the direction toward the left and rightlateral edges or sides 82, 83 of the carriage 07. The result of this isthat during a cleaning move of the carriage 07 from the right endposition B in to the left end position A, the respectively wedge—likeacting doctor blade disks 74 to 76 mechanically reduce the deposits ofink and paper fibers, which for example have been irregularly built up,to a minimum thickness . An overstress of the work edges 79 is avoidedby the wedge-shaped or angled arrangement of the doctor blade disks. Inthis case, a minimal distance of approximately 0.02 mm remains betweenthe surface 28 of the paper guide roller 04 and the doctor blade disk 76located closest to it.

If the two spaced doctor blade devices 72, 73 are arranged as seen inFIG. 1, the work edges 79 of the two doctor blade devices 72, 73 form anopening angle of 164° to 174°, for example.

The filling connection 38 for the fluid reservoir 37, as well as thedisposal connector 45 for the catch basin 42 of the carriage 07 are eachrespectively connected by intermediate lines 89, 91 with a centralsupply line 92, or with a central disposal line 93. This can take place,for example, in that the intermediate lines 89, 91 between the carriage07 and the supply line 92, or the disposal line 93, are designed astrailing lines. It is furthermore also possible to fill, or empty, thefluid reservoir 37 and the catch basin 42 of the carriage 07 via theintermediate lines 89, 91 while the carriage 07 is parked in the rightend position B shown in FIG. 3.

Viewed in the carriage 07 operating direction, i.e. in the axialdirection of the roller 04, the respective doctor blade device 72, 73 isarranged ahead of or before, in the direction of carriage travel, thebrushes 13, 14, 16, 17. In this way, two differently operating cleaningelements 13, 14; 16, 17; 72, 73 act on the roller 04, and preferably actsimultaneously, i.e. the doctor blade device 72, 73 is used forpre-cleaning.

The cleaning device of the present invention can be operated as follows:a sensor 94, which is connected via an electrical line 95 with thecentral electrical line 88, determines whether a paper web 96, as shownin FIGS. 2 and 3 has been provided for driving the paper guide roller 04to be cleaned, or for driving another similar roller to be cleaned, forexample a draw-in roller. It is, of course, also possible for a paperweb 97, as shown in dashed lines in FIG. 2, to be wrapped around a paperguide roller 04 by 180°. If no paper web 96, 97 is provided, the liftmagnet 67, together with the motor 66, is switched on by operation ofthe sensor 94, so that the drive pulley 61 turns. The motor 47 is actedupon at the same time, so the carriage 07 moves out of the end positionB in the direction toward the end position A.

Depending on a preselected mode of operation of the cleaning device 01the surface 28 of the paper guide roller 04 can either be wiped off, orcan be both wiped off and sprayed with cleaning fluid or, for intensetreatment, can later be processed by the rotating brushes 13, 14, 16,17. In the last case, i.e. with intense brush cleaning, it is logical toretract the brush holder 11, 12 in the z-direction after reaching theend position A. It is prevented by this retraction that the fluid filmapplied to the surface 28 of the paper guide roller 04 is subsequentlydestroyed.

The movement, for example the retraction of the brush holders 11, 12 inthe z axis direction, as seen in FIG. 2, can take place by use of aknown, remotely controllable actuator, not specifically represented, forexample a servo motor fixed in place on the carriage, and provided witha threaded spindle seated fixed in place on the carriage.

It is recommended to clean the paper guide or draw-in rollers at the endof a production run and to apply a liquid separating agent, for examplea mixture of silicon and water, to them prior to the next start ofproduction.

The reservoir 37 can be selectively filled, using the filling connection38, with cleaning fluid or with liquid separating agent. The amount offluid taken up by the reservoir 37 is sufficient for spraying a rollersurface.

During filling of the reservoir, an excess of cleaning fluid, forexample 20% more cleaning fluid, is supplied to the reservoir 37, whichexcess cleaning fluid then leaves the reservoir 37 through the overflowline 41 and is thus used for rinsing the catch basin 42.

While a preferred embodiment of a device for cleaning a roller inaccordance with the present invention has been set forth fully andcompletely hereinabove, it will be apparent to one of skill in the artthat a number of changes in, for example, the particular type ofprinting press, the overall size of the device, and the like could bemade without departing from the true spirit and scope of the subjectinvention which is accordingly to be limited only be the followingclaims.

What is claimed is:
 1. A device adapted for cleaning a roller of arotary printing press comprising: a plurality of rotatable cleaningelements, each having an axis of rotation arranged not parallel with anaxis of rotation of the roller, said plurality of rotatable cleaningelements being arranged next to each other along the axis of rotation ofthe roller, at least two of said plurality of rotatable cleaningelements having opposite directions of rotation; a carriage supportingsaid plurality of rotatable cleaning elements, said carriage beingdisplaceable along the axis of rotation of the roller; a drive motor onsaid carriage for rotating said plurality of cleaning elements; anactuator on said carriage for moving said plurality of rotatablecleaning elements in a radial direction with respect to the roller to becleaned; and a doctor blade device, said doctor blade device beinglocated before, in a direction of travel of said device along theroller, said plurality of rotatable cleaning elements.
 2. The device ofclaim 1 wherein said axis of rotation of said cleaning elements forms anangle of −45° to +45° with a radial line extending through a contactzone of said cleaning elements and the roller.
 3. The device of claim 1further including at least one opening for cleaning fluid in each ofsaid plurality of rotatable cleaning elements.
 4. The device of claim 3wherein said opening is arranged inside each of said plurality ofrotatable cleaning elements.
 5. The device of claim 1 further includingmeans to displace said device in the axial direction of the roller. 6.The device of claim 1 wherein each said cleaning element is a brush. 7.The device of claim 6 wherein each said brush includes bristles.
 8. Thedevice of claim 6 wherein said brushes and said doctor blade device areoperable at the same time.
 9. The device of claim 1 wherein each saidcleaning element is a front brush.
 10. The device of claim 9 furtherincluding a doctor blade device, said doctor blade device being locatedbefore, in a direction of travel of said device along the roller, saidplurality of front brushes.
 11. The device of claim 10 wherein saidfront brushes and said doctor blade device are operable at the sametime.
 12. The device of claim 1 wherein the roller is a guide roller.13. A device adapted for cleaning a roller of a rotary printing presscomprising: a plurality of rotatable cleaning elements, each having anaxis of rotation arranged not parallel with an axis of rotation of theroller, said plurality of rotatable cleaning elements being arrangednext to each other with respect to the axis of rotation of the rollerand behind each other in a circumferential direction of the roller; acarriage supporting said plurality of rotatable cleaning elements, saidcarriage being displaceable along the axis of rotation of the roller; adrive motor on said carriage for rotating said plurality of cleaningelements; an actuator on said carriage for moving said plurality ofrotatable cleaning elements in a radial direction with respect to theroller to be cleaned; and a doctor blade device, said doctor bladedevice being located before, in a direction of travel of said devicealong the roller, said plurality of rotatable cleaning elements.
 14. Thedevice of claim 13 wherein said axis of rotation of said cleaningelements forms an angle of −45° to +45° with a radial line extendingthrough a contact zone of said cleaning elements and the roller.
 15. Thedevice of claim 13 further including at least one opening for cleaningfluid in each of said plurality of rotatable cleaning elements.
 16. Thedevice of claim 15 wherein said opening is arranged inside each of saidplurality of rotatable cleaning elements.
 17. The device of claim 13further including means to displace said device in the axial directionof the roller.
 18. The device of claim 13 wherein each said cleaningelement is a brush.
 19. The device of claim 18 wherein each said brushincludes bristles.
 20. The device of claim 18 wherein said brushes andsaid doctor blade device are operable at the same time.
 21. The deviceof claim 13 wherein each said cleaning element is a front brush.
 22. Thedevice of claim 21 further including a doctor blade device, said doctorblade device being located before, in a direction of travel of saiddevice along the roller, said plurality of front brushes.
 23. The deviceof claim 22 wherein said front brushes and said doctor blade device areoperable at the same time.
 24. The device of claim 13 wherein the rolleris a guide roller.